JPS5973736A - Vehicle weight measuring method - Google Patents

Abstract

PURPOSE:To measure axle loads accurately, to measure the total weight of a vehicle highly accurately together with the axle loads, and to make it possible to perform automatic totalling and the judgement of the kind of the vehicle, without flattening the upper surface of a measuring girder and the surfaces of roads before and after the girder. CONSTITUTION:The length of a bridge shaped girder is longer than the longest wheel base of a vehicle. On said girder, shearing force detectors 5A-5L are arranged at an equal interval, which is shorter than the shortest wheel base. The outputs of the detectors 5A-5L are inputted to a control circuit 9. When a vehicle 6 passes on the girder 1 from the lect to the right, the detector 5A sends the output corresponding the weight of front wheels (front axle) 7. Then the detectors 5B-5L sequentially output the weights. The front axle outputs and the rear axle outputs are sequentially overlapped in the order of the outputs, and upper envelops are formed. The half period to several periods of the synthesized waves are averaged by a procedure 11. Then axle loads WF and WB of the front axle and the rear axle are obtained by a procedure 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the weight of a moving vehicle by measuring the axle load of the vehicle.

A running vehicle vibrates due to each spring system and shifts its center of gravity, so its axle load fluctuates around the axle load when it is stationary. Conventional axle load measurement uses a detection plate for axle load measurement (a loading plate is placed on the lower membrane on top of multiple load transducers).
Since the value is small, only a temporary value of the fluctuating axle load value can be measured, which has the disadvantage that the measurement results are inaccurate.

In order to reduce this variation in the axle load value, it is necessary to make not only the detection plate itself but also a certain length of the road surface in front of and behind the detection plate strictly flat. However, this flat finishing is technically quite difficult and economically disadvantageous.

By the way, to measure the axle load and total vehicle weight,
The axle load values of each axle of one vehicle are totaled, but in this case, it is necessary to determine whether the axle load is of the same vehicle or another vehicle. This discrimination method includes a visual method and an automatic discrimination method using a combination of devices such as phototubes, loop coils, speedometers, etc. without visual inspection.

The latter type of conventional vehicle identification device is said to be complicated because it electrically processes detection information from single-function detectors such as phototubes, loop coils, and speedometers to determine the vehicle type. This method has its drawbacks, and it is not always possible to accurately identify the vehicle type.

The present invention was made in view of the above circumstances, and its purpose is to be able to accurately measure the axle load without flattening the top surface of the measuring girder and the road surface in front and behind it, and to measure the axle load based on this axle load. An object of the present invention is to provide a vehicle weight measuring method that can measure the total weight of a vehicle with high precision.

Furthermore, a second object of the present invention is to provide a vehicle weight measuring method that can measure the axle load of a vehicle and automatically total the axle loads of one vehicle to determine the total vehicle weight.

Furthermore, a third object of the present invention is to provide a vehicle weight measuring method that allows the type of vehicle to be measured to be determined.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing measurement stringers used in carrying out the method of the present invention and their arrangement, and FIG. 2 is a longitudinal cross-sectional view of the same. In the figure, the girder 1 is arranged with its upper surface aligned at the same height as the road surface 2.

A pit 3 for maintenance and inspection is excavated on the road, and supports 4, 4 are provided at both left and right ends of this pit 3 as fulcrums for the girder 1. , 4 is held substantially horizontally. In this embodiment, the girder 1 has a flat plate part 1a of one lane width whose upper surface is arranged at the same height as the road surface 2, and a predetermined height on the lower surface side of the flat plate part 1a, and has a It consists of two cross-shaped plate parts 1b and IC extending in parallel in the left-right direction in FIG. 2, and has a bridge-like shape that is longer than the longest distance between the axes of the vehicle to be measured. Cross-shaped plate part 11
), shear force detection sensors 5 (
In this case, strain gauges) are attached at equally spaced positions by adhesive or other means. The strain gauges as the shear force detection sensor 5 are formed in a set of two so as to be able to detect the shear force, and each strain gauge has four strain gauges for each plate portion of the flat plate portion 1a.
They are attached at the same position, shifted by 5° and 135°, and intersect with each other. The above-mentioned equally spaced sections are set to be equal to or less than the shortest distance between the axes of the vehicle to be measured, and as shown in FIG. ~5L is configured.

Here, the section corresponding to the detectors 58 to 5L is assumed to be 8 to L.

FIG. 3 is a block diagram showing a schematic configuration of a circuit showing an embodiment of the method of the present invention and a signal processing procedure in the circuit, and FIG.
a) is an explanatory diagram showing a state in which a vehicle runs on a measurement girder;
The same figure (b) shows each detector 58 to 5 when a vehicle passes.
FIG. 5, a timing diagram showing the output of L, is a waveform diagram in which the axle load waveforms of each output shown in FIG. 4 are combined for the front axle and the rear axle, respectively.

First, a method for measuring an axle load value will be explained with reference to FIGS. 3 to 5.

In FIG. 3, each output from each detector 58 to 5L is
The signal is input to the control circuit 9. Now, as shown in FIG. 4(a), when the vehicle 6 passes over the girder 1 from left to right, the detector 5
A outputs an output according to the weight of the front wheel (front axle) 7, and the output is read by the output detectors 5B, 50, etc.

5 L outputs j sequentially. The output waveforms of each detector at this time are expressed as A7 to L7, with time plotted on the horizontal axis and voltage plotted on the vertical axis, as shown in FIG. 4(b) 1%. Similarly, the output waveforms of the respective detectors depending on the weight of the rear wheel (rear axle) 80 are as shown in A8 to r, s (xIs to L8 are not shown). The previous export power A exhibiting such a waveform
7 to L7 and the rear shaft outputs A8 to L8 are sequentially superimposed according to the order in which they are output, and their head envelopes are synthesized. 2T) in step 11 and calculate each axle load W of the front and rear axles.
Find F and W B in step 12. The fluctuation period of this head envelope is based on the body vibration of the vehicle being measured. Therefore, when detecting axle load, good measurement results can be obtained by averaging the output over at least half of the fluctuation period. . The axle load value obtained in this way can be obtained by visually adding the number of axles for one vehicle, or by controlling a signal indicating that the vehicle is a vehicle by a photocell or a signal according to the vehicle identification procedure described below. - The total weight of the vehicle is determined (step 13).

Figure 6 (a) is an explanatory diagram showing the state in which two vehicles are running on the measurement girder, and Figure 6 (b) shows the output of each detector as a digital signal when those vehicles pass. A timing diagram is shown below. Next, with reference to FIG. 6 and FIG. 3, a method for determining whether or not the obtained axle load outputs are from the same vehicle will be explained. The signals from the detectors 5A to 5L input to the control circuit 9 are digitally processed and made into waveforms that only indicate the presence or absence of output as shown in the timing chart in FIG. 1
5, an output A' 15 is generated in section A, and the rear shaft 16
The output A]6 is generated. Similarly, the following vehicle 17
The front shaft 18 generates an output A18, and the rear shaft 19 generates an output A19. The same applies to other sections BL. From such output pulses, the axle load can be determined by knowing the timing difference t between the output pulses of the front axle or the rear axle passing through adjacent sections. That is, the axle load V can be determined as (2)=section distance, /1 (step 20). Output pulses that occur in different sections at the same timing represent the next axis. Compare the passing timing difference between these adjacent sections, for example, t2 and 11. Step 21) If the two are equal (however, if t2 and 11 are equal), then (including cases within the allowable range) −
It is determined that it is a vehicle (step 22). In the case of the example shown in FIG. 6, the output pulse A15. E1
5 is generated, and the timing difference with the pulse B16°F15 generated in the next section is t2 and t, respectively.
It becomes l. In this case, since t2 and tl are equal, it can be seen that the front and rear axles of the same vehicle generate pulses in sections E and A, and therefore in sections A to E.

Alternatively, 13 to F are determined as the distance between the axes (step 23). This distance between the axes is tentatively represented as LBF on the timing diagram shown in FIG.

Based on the output 116 of another interval ■ whose timing matches the next output AI8 generated in the interval, similarly calculate the timing differences t3 and 14 between the outputs generated in the adjacent intervals n and J, respectively (step 20). , compare both (step 21)
. Since the timing differences t3 and t4 are not the same, it can be seen that the two axles of the same vehicle are not the same (step 22), but the inter-axle distances L D and T are measured (step 23). This L IJ
J indicates the inter-axle distance between the rear axle of the preceding vehicle and the front axle of the following vehicle. These inter-axle distances Ln, r are not added to the previously determined inter-axle distance LBF, but the total inter-axle distance is calculated (step 25). If t3 and t4 are equal, LBJ
is added to the LBF to determine the total center distance. This distance between the axles is also constantly scanned and measured at the same time as the axle load and U-sama move to adjacent sections sequentially, and when the distance between each axle is compared in step 24, from this change (
Step 22), - The vehicle can be identified (Step 22).

Thus, the axle load values of each axle obtained in steps 0 to 12 are added according to the signal from the one-vehicle discrimination step 22, and the total weight for the -vehicle is determined (step 13). The type of vehicle, so-called vehicle type, is determined based on the total weight and total distance between the axles.

Although the procedure shown in Fig. 3 is as described above, it is not necessary to measure the distance between the axles in order to determine whether the vehicles are the same. It is sufficient to detect a change. In addition, to identify identical vehicles,
Steps 23 and 24 may be used to change only the distance between the axes.

According to the embodiment shown in Fig. 3, not only can the axle load value be measured with high precision, but also the total weight and total distance between the axles can be measured by determining whether the vehicle is the same, making it possible to accurately and reliably identify the vehicle type. This makes it possible to monitor and control overloaded vehicles, and to save labor and make toll road toll collection operations unmanned.

As detailed above, according to the present invention, the axle load can be measured accurately without eliminating the vibration of the running vehicle by intentionally finishing the top surface of the measuring girder and the road surface in front and behind it to be flat. The total weight of the vehicle to be measured can be measured with high accuracy.

Further, according to the second invention, it is possible to easily determine whether or not the shafts belong to the same vehicle by measuring changes in shaft speed, and thereby the total weight can be automatically measured. Therefore, according to the present invention, it is possible to accurately and efficiently control and monitor overloaded and speeding vehicles.

Furthermore, according to the third invention, as in the case of the second invention, measurement of the total weight, monitoring and enforcement of overloaded tanks can be performed accurately and efficiently, and accurate total weight and total axle distance can be obtained. Since it is possible to determine the type of vehicle being measured based on the number of axles and the total number of axles, it becomes easier and more reliable to control vehicles that violate the loaded weight, and it also greatly simplifies ticketing and toll collection operations on toll roads. It has the advantage of being unmanned.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the measuring girders used in carrying out the method of the present invention and their arrangement, FIG. 2 is a longitudinal sectional view of FIG. 1, and FIG. 3 is a schematic configuration of a circuit showing an embodiment of the present invention. FIG. 4(a) is an explanatory diagram showing the state in which the vehicle is running on the measurement girder, and FIG. 4(b) is a block diagram showing the signal processing procedure in the circuit.
5 is a timing diagram showing the output of each detector when a vehicle passes by, FIG. 5 is a waveform diagram that combines the axle load waveforms of each output shown in FIG.
(a) is an explanatory diagram showing the state in which two vehicles are running on the measurement girder, and (b) is a timing diagram that digitizes and represents the output of each detector when those vehicles pass. . 1... Measuring girder, 1a... Flat plate part,
Ib, Ic...Bar-shaped plate portion, 2...Road surface, 3...
...Maintenance and inspection pins 1~, 4...Supports,
5... Sensor for shear force detection, 58-5L... Detector, A-L... Section, 6, 14, 17... Vehicle, 7, 15. 1
8... Image front axis (front wheel), 8, 16, 19...
・Rear axle (rear wheel), 9...control circuit, 10, II, 12, 1.3, 20, 21, 22, 23,
24, 25.26 -... procedure, tl, t2.
t3. t4... Timing difference of output pulses between adjacent sections, LBF, LBJ... Distance between axes. 1 j:=j+ p;; 2 Figure 3 Figure 4 (C)) Figure 5

Claims (3)

[Claims] (1) In a method of measuring the weight of a moving vehicle by measuring the axle load of the vehicle, a bridge-like girder having a length greater than or equal to the longest axle distance of the vehicle has equally spaced sections less than or equal to the shortest axle distance. A detector for detecting shear force is provided, and when the vehicle runs on the girder, the axle load waveforms output from each of the detectors are sequentially superimposed, and the axle load waveform based on the body vibration of the vehicle is The axle load of one axle is measured by averaging the output over at least a half cycle of the fluctuation cycle of the head envelope, and the weight of one vehicle in motion is determined by summing up each axle load of the same vehicle. Characteristic vehicle weight measurement method. (2) In a method of measuring the weight of a moving vehicle by measuring the axle load of the vehicle, a bridge-like girder with a length greater than or equal to the longest axle distance of the vehicle has equally spaced sections less than or equal to the shortest axle distance. A detector for detecting shear force is provided in the vehicle, and when the vehicle runs on the girder, the axle load waveforms obtained from each of the detectors are sequentially superimposed, and the head of the axle load waveform based on the body vibration of the vehicle is Calculate the axle load of one shaft by averaging the output over at least half the period of variation of the partial envelope, calculate the shaft speed from the movement of the signal in each section, and calculate the shaft speed from the obtained change in the shaft speed. A method for measuring vehicle weight, characterized in that the weight of one running vehicle is measured by determining whether the axles belong to the same vehicle or not, and totaling the axle loads obtained by the calculation. (3) In a method of measuring the weight of a moving vehicle by measuring the axle load of the vehicle, a bridge-like girder having a length greater than or equal to the longest axle distance of the vehicle has equally spaced sections less than or equal to the shortest axle distance. A detector for detecting shear force is provided in the vehicle, and when the vehicle runs on the girder, the axle load waveforms obtained from each of the detectors are sequentially superimposed, and the head of the axle load waveform based on the body vibration of the vehicle is The axle load of one axis is calculated by averaging the output over at least half the period of fluctuation of the part envelope, and the distance between the axles is measured from the interval distance where the output of the detector is simultaneously output. A vehicle weight measurement characterized in that it is determined from the change in the distance between the axles whether the axles are of the same vehicle or not, and the axle load obtained by the calculation is calculated to measure the weight of one moving vehicle. Method.